Wilbur Wright to Octave Chanute

Dayton, May 13, 1900

For some years I have been afflicted with the belief
that flight is possible to man. My disease has increased in severity
and I feel that it will soon cost me an increased amount of money
if not my life. I have been trying to arrange my affairs in such
a way that I can devote my entire time for a few months to experiment
in this field.

My general ideas of the subject are similar to those
held by most practical experimenters, to wit: that what is chiefly
needed is skill rather than machinery. The flight of the buzzard
and similar sailers is a convincing demonstration of the value
of skill, and the partial needlessness of motors. It is possible
to fly without motors, but not without knowledge & skill.
This I conceive to be fortunate, for man, by reason of his greater
intellect, can more reasonably hope to equal birds in knowledge,
than to equal nature in the perfection of her machinery.

Assuming then that Lilienthal was correct in his
ideas of the principles on which man should proceed, I conceive
that his failure was due chiefly to the inadequacy of his method,
and of his apparatus. As to his method, the fact that in five
years' time he spent only about five hours, altogether, in actual
flight is sufficient to show that his method was inadequate. Even
the simplest intellectual or acrobatic feats could never be learned
with so short practice, and even Methuselah could never have become
an expert stenographer with one hour per year for practice. I
also conceive Lilienthal's apparatus to be inadequate not only
from the fact that he failed, but my observations of the flight
of birds convince me
that birds use more positive and energetic methods of regaining
equilibrium than that of shifting the center of gravity.

With this general statement of my principles and
belief I will proceed to describe the plan and apparatus it is
my intention to test. In explaining these, my object is to learn
to what extent similar plans have been tested and found to be
failures, and also to obtain such suggestions as your great knowledge
and experience might enable you to give me. I make no secret of
my plans for the reason that I believe no financial profit will
accrue to the inventor of the first flying machine, and that only
those who are willing to give as well as to receive suggestions
can hope to link their names with the honor of its discovery.
The problem is too great for one man alone and unaided to solve
in secret.

My plan then is this. I shall in a suitable locality
erect a light tower about one hundred and fifty feet high. A rope
passing over a pulley at the top will serve as a sort of kite
string. It will be so counterbalanced that when the rope is drawn
out one hundred & fifty feet it will sustain a pull equal
to the weight of the operator and apparatus or nearly so. The
wind will blow the machine out from the base of the tower and
the weight will be sustained partly by the upward pull of the
rope and partly by the lift of the wind. The counterbalance will
be so arranged that the pull decreases as the line becomes shorter
and ceases entirely when its length has been decreased to one
hundred feet. The aim will be to eventually practice in a wind
capable of sustaining the operator at a height equal to the top
of the tower. The pull of the rope will take the place of a motor
in counteracting drift. I see, of course, that the pull of the
rope will introduce complications which are not met in free flight,
but if the plan will only enable me to remain in the air for practice
by the hour instead of by the second, I hope to acquire skill
sufficient to overcome both these difficulties and those inherent
to flight. Knowledge and skill in handling the machine are absolute
essentials to flight and it is impossible to obtain them without
extensive practice. The method employed by Mr. Pilcher of towing
with horses in many respects is better than that I propose to
employ, but offers no guarantee that the experimenter will escape
accident long enough to acquire skill sufficient to prevent accident.
In my plan I rely on the
rope and counterbalance to at least break the force
of a fall. My observation of the flight of buzzards leads me to
believe that they regain their lateral balance, when partly overturned
by a gust of wind, by a torsion of the tips of the wings. If the
rear edge of the right wing tip is twisted upward and the left
downward the bird becomes an animated windmill and instantly begins
to turn, a line from its head to its tail being the axis. It thus
regains its level even if thrown on its beam ends, so to speak,
as I have frequently seen them. I think the bird also in general
retains its lateral equilibrium, partly by presenting its two
wings at different angles to the wind, and partly by drawing in
one wing, thus reducing its area. I incline to the belief that
the first is the more important and usual method. In the apparatus
I intend to employ I make use of the torsion principle. In appearance
it is very similar to the "double-deck" machine
with which the experiments of yourself and Mr. Herring were conducted
in 1896-7. The point on which it differs in principle is
that the cross-stays which prevent the upper plane from moving
forward and backward are removed, and each end of the upper plane
is independently moved forward or backward with respect to the
lower plane by a suitable lever or other arrangement. By this
plan the whole upper plane may be moved forward or backward, to
attain longitudinal equilibrium, by moving both hands forward
or backward together. Lateral equilibrium is gained by moving
one end more than the other or by moving them in opposite directions.
If you will make a square cardboard tube two inches in diameter
and eight or ten long and choose two sides for your planes you
will at once see the torsional effect of moving one end of the
upper plane forward and the other backward, and how this effect
is attained without sacrificing lateral stiffness. My plan is
to attach the tail rigidly to the rear upright stays which connect
the planes, the effect of which will be that when the upper plane
is thrown forward the end of the tail is elevated, so that the
tail assists gravity in restoring longitudinal balance. My experiments
hitherto with this apparatus have been confined to machines spreading
about fifteen square feet of surface, and have been sufficiently
encouraging to induce me to lay plans for a trial with [a] full-sized
machine.

My business requires that my experimental work be
confined to the months between September and January and I would
be particularly thankful for advice as to a suitable locality
where I could depend on winds of about fifteen miles per hour
without rain or too inclement weather. I am certain that such
localities are rare.

I have your
Progress
in Flying Machines and your articles in the
Annuals of '95*,
'96, &
'97, as
also your recent articles in the Independent. If you can
give me information as to where an account of Pilcher's experiments
can be obtained I would greatly appreciate your kindness.